Combines for harvesting grain crops such as wheat, barley, oats and the like have been known for many years. The use of combines to harvest grain crops of this type has permitted the efficient production of said type grain grown on very extensive fields with minimum use of labor and consumption of time. Progressively, combines have been developed capable of harvesting wider swaths of grain than previously harvested by earlier combines and this has resulted in the combines being larger and more powerful, as well as more expensive than such earlier combines.
The increase in cost of such aforementioned improved combines also has led to attempts to develop combines capable of harvesting a wider variety of seed or grain crops than capable of being handled by earlier combines, adapting such combines for said harvesting of a wider variety of crops however being made possible by minimum requirements of exchanging certain elements of the combine for others, especially the headers and elevators. For example, harvesting corn requires a different type of header to cut and elevate the corn stalks and ears to the threshing mechanism than is required for harvesting wheat, oats, and similar headed stalk crops. Further, harvesting bean or other pod-like crops requires different header structures from those used to harvest corn and wheat-like crops for example.
With respect to the threshing and separating mechanism of the combine however, it is preferred that the same be adapted to thresh and separate substantially all types of seed type crops for purposes of threshing and separating the seed from the stalks, vines and other waste material, the latter being discharged upon the field as the combine moves along the same in a harvesting operation.
It readily can be appreciated that adapting a combine to harvest, thresh and separate a wide variety of crop materials of the type referred to above makes it necessary that the combine handle a substantial variety of different types of crops varying as to bulk, moisture content, toughness of the stalk or vine included in the crops and otherwise. Preferably, by adjusting the spacings between the rotors and concaves in threshing and separating areas of the combine, this part of the apparatus has been developed sucessfully and comprises, for example, the subject matter of the following prior patents, all of which are assigned to the assignee of the present invention.
______________________________________ 3,626,472 Dec. 7, 1971 3,645,270 Feb. 29, 1972 3,664,100 May 23, 1972 3,794,047 Feb. 26, 1974 ______________________________________
Notwithstanding the capabilities of the inventions comprising the subject matter of the foregoing patents, it now has been found that additional features render such universal type combines even more efficient and effective. For example, referring to said aforementioned U.S. Pat. Nos. 3,626,472 and 3,794,047 there is a ramp which extends between the upper end of the bottom plate of the elevator, upwardly and rearwardly toward the forward end of the rotor of the threshing and separating mechanism. Said ramp also constitutes a transition or feed plate and, as shown in said patents, said ramp or feed plate is of a fixed nature. Said combines are of the type in which the lower span of the elevator feeds the crop material upwardly and rearwardly toward the forward end of the rotors, delivering the same to the rotors in a so-called undershot manner. The rotors conventionally employ an auger at the forward end thereof which is rotated by power means in a direction to feed the crop material inwardly to the rotors for engagement by said rotors and concaves associated therewith in the combine which is of the axial flow type, the same being the type to which the present invention pertains.
Depending upon the nature and character of the crop and especially the toughness thereof, moisture content, bulk and the like, it has been found that a fixed type of ramp, transition or feed plate to guide the crop material from the upper end of the elevator toward the forward end of the rotor of the combine is not readily capable of accommodating all types of such crop conditions efficiently. For example, if the bulk is too great at any instant, because of a sudden surge or momentary increase in the amount of the crop material being delivered by the elevator to the rotor, excess material which cannot be accepted by the auger and rotor will be returned by the upper span of the elevator toward the header for recycling of the same by the lower span of the elevator. Obviously, such operation is wasteful and undesirable. Therefor, it is the principle object of the present invention to render a combine of the type described capable of accommodating a wide variety of different types of crops, such as those varying in bulk, moisture content, and the like by including certain improvements consitituting the essential features of the present invention, details of which are described hereinafter.